The radiographic X-ray device based on the double imaging apparatus method, which have hitherto been used typically in healthcare institutions such as hospitals, have had a pair of imaging apparatuses 81 and 82 as shown in FIG. 6. X-ray imaging system 81 comprises an X-ray tube 83 for radiating X-rays and an X-ray detector 84 for detecting transmitted X-rays, which are arranged to face each other and are supported on each end of a C-shaped support arm 85, while X-ray imaging system 82 comprises an X-ray tube 86 for radiating X-rays and an X-ray detector 87 for detecting transmitted X-rays, which are arranged to face each other and are supported on each end of a C-shaped support arm 88, wherein X-ray imaging systems 81 and 82 are moved by rotating and translating C-shaped support arms 85 and 88, thus setting the orientations (shooting directions) and positions (shooting positions) of X-ray imaging systems 81 and 82 respectively to meet the needs of image studies.
Therefore, in the case of the radiographic X-ray device based on the double imaging apparatus method, two X-ray imaging systems 81 and 82 are set up independently in terms of their orientations and positions, thus enabling radiography of a same location of a specimen body M on a top plate 89 from different directions simultaneously by taking X-ray images with X-ray imaging systems 81 and 82 from different directions simultaneously, or radiography of different locations of specimen body M on top plate 89 simultaneously.
The radiographic X-ray device of the prior art based on the double imaging apparatus method, however, has had a problem that X-ray imaging systems 81 and 82 may come in contact with each other while X-ray imaging systems 81 and 82 are in motion. Depending on how the contact occur, damages to X-ray tubes 83 and 86 as well as to X-ray detectors 84 and 87 may occur.
A countermeasure to this concern has been to avoid equipment damages by means of attaching cushioning materials on the areas where contacts are expected to soften the impacts. However, it is difficult to attach cushioning materials to all the places where contacts are expected. Moreover, contact impacts are often be greater than that can be absorbed by cushioning materials.
Another countermeasure has been to have proximity sensors installed at locations of X-ray imaging systems 81 and 82 where contacts may occur so that an alarm can be sounded to call the operator's attention or to stop the motions of X-ray imaging systems 81 and 82 if X-ray imaging systems 81 and 82 come too close to each other. However, it is difficult to install proximity sensors at all locations where contact may occur, so that it is not a secure measure to avoid contacts.
Therefore, the operator has to monitor X-ray imaging systems 81 and 82 visually all the time, and move X-ray imaging systems 81 and 82 at very slow speeds when contacts are likely to occur in order try to avoid contacts. As a result, the picture-taking time tends to be longer, making it an inefficient and painful operation for the operator.
Another possibility is to measure positional relations between X-ray imaging systems 81 and 82 for all possible cases of contacts and register all positional relation data as in a form of a table in order to avoid contacts between X-ray imaging systems 81 and 82 while X-ray imaging systems 81 and 82 are in motion by constantly checking each positional relation data, but the size of the data involved can be enormous if it were to cover all the possible cases of positional relations of X-ray imaging systems 81 and 82 and it is an unrealistic solution in accordance with the work involved in collecting the data and the memory size of data to be registered.